用Servlet实现统计网站被访问次数的功能

思路：

1.新建一个Servlet类继承HttpServlet，重写doGet（）和doPost（）方法；
2.在doPost方法中调用doGet（）方法，在doGet()方法中实现统计网站被访问次数的功能，用户每请求一次servlet，使得访问次数times加1；
3.获取ServletContext，通过它的功能记住上一次访问后的次数。

实现代码：

package readPath;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class test001 extends HttpServlet {
	private static final long serialVersionUID = 1L;
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
	 response.setContentType("text/html;charset=GB2312");
	 //设置编码，不然中文会变成乱码
	 ServletContext context = this.getServletContext();
	 PrintWriter out = response.getWriter();
	 Integer times =(Integer)context.getAttribute("times");
	 if(times==null) {
		 times = new Integer(1);
	 }else {
		 times = new Integer(times.intValue()+1);
	 }
	 out.println("");
	 out.println("当前页面被访问过了");
	 out.println(""+times+"次");
	 //设置属性，将times保存到当前的上下文中
	 context.setAttribute("times", times);
	 
	}
	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		// TODO Auto-generated method stub
		this.doGet(req, resp);
	}

}

运行结果：